NEET Test 198

Formic acid and acetic acid can be distinguished using 2,4-dinitrophenylhydrazine. 

Formic acid is having aldehyde group, so it answers the above test. Forming yellow colour precipitate of 2,4-dinitro phenyl hydrazone. Whereas acetic acid does not.

In certain seeds, the dormancy of the seeds is due to the presence of certain germination inhibitors like coumarin, ferulic acid, abscisic acid, etc. These may be present in the endosperm, embryo, testa, or juice or pulp of the fruit.

Completoria is a fungal genus in the monotypic family Completoriaceae, of the order Entomophthorales. Completoria is itself monotypic, containing a single species, Completoria complens. The species is rare, known only from greenhouse cultures where it grows as an obligate intracellular parasite of fern gametophytes.

Glauber’s salt is the decahydrate form of sodium sulfate. It is also known as mirabilite. The chemical formula of Glauber’s salt can be written as Na₂SO₄.10H₂O. Glauber’s salt is known to be a vitreous mineral with a white or colorless appearance that is formed as an evaporite from brines containing sodium sulfate.

Compound is β -hydroxy aldehyde hence the reaction is aldol addition. A and B can be known by retro aldol addition as follows:

As per Mendel's Law of Segregation, "alleles segregate randomly into gametes: When gametes are formed, each allele of one parent segregates randomly into the gametes, such that half of the parent's gametes carry each allele."

The cross between parents with genotype produces the following progenies -

Progeny with genotype heterozygous for all gene is 1 out of 8 types. Thus, probability is .

Darwin studied the flora and fauna of Galapagos Islands, a chain of islands on the west coast of South America. There he found an amazing range of creatures existing. He found that there were many varieties of small blackbirds in these islands which differed mainly in the shape of beaks and feeding habits. These varieties of small blackbirds were later called Darwin's Finches. After analyzing them, he realized that all of these varieties evolved on the same island itself and were not from separate areas. He conjectured that these varieties evolved from the original seedeating ancestor bird which was present in South America. Some of them flew to these islands and according to the needs of different environments, they developed different shapes of beaks and feeding habits. Some became insect-eating, some fruit-eating, some cactus eating, etc.

Since the diode is reversed biased, only drift current exists in the circuit which is 20μA.

Potential drop across 15Ω resistor = 15Ω × 20μA

= 300μV

=0.0003V

Potential difference across the diode = 4 − 0.0003

= 3.99

= 4V